METABOLISM 309 



but they were obscured by a much more striking conse- 

 quence: the loss of the ability to oxidize sugar. 



We must bear in mind that the oxidation of sugar does 

 not take place in the pancreas and yet the influence of 

 that gland is one of its necessary conditions. It has to 

 be assumed that some agent derived from the pancreatic 

 cells enters the circulation and travels to the tissues far 

 and wide, conferring on them the power to set free and 

 utilize the energy that is latent in the sugar molecules. 

 The agent concerned is a hormone as denned in Chapter 

 XV. It is not precisely an enzyme but reminds us of 

 that type of substance in that it is known by its effects 

 rather than as an isolated body . 



Lack of the pancreatic hormone with consequent lack 

 of the capacity to make use of dextrose is the central 

 condition in the disease diabetes. This is popularly 

 supposed to be a " kidney trouble" but it is not. When 

 the body cannot oxidize sugar the continued addition of 

 this digestive product to the blood leads to hypergly- 

 cemia. An escape of sugar in the urine is then to be 

 expected, for normal kidneys always let it pass when the 

 concentration on the blood exceeds a certain low limit. 

 Unlike alimentary glycosuria, the diabetic state means 

 an abundant and more or less continuous loss of sugar. 

 In fully developed cases all the sugar entering the blood 

 is transferred to the urine without having contributed to 

 the activities of the tissues. * 



It might be anticipated that in diabetes the glycogen 

 of the liver and muscles would be maximal in amount. 

 On the contrary the power to make and hold this deriva- 

 tive of sugar seems to be lost along with the ability to 

 oxidize. The pancreatic hormone appears to confer 

 both the power to oxidize sugar and the power to convert 

 it into glycogen. When diabetes reaches its full intensity 

 and no dextrose can be broken down there follows, as 

 already noted, a faulty fat metabolism and acidosis of the 

 gravest kind. 



